Pirates were 19-12 up at half-time as Dan Hiscocks, Arthur Relton and Morgan Nelson crossed for the hosts while Nathan Langdon and Jasper McGuire replied for the visitors.
McGuire went over two minutes after the break to level the scores before Pirates’ impressive maul, which had forced Nelson over before the break, took control.
Pritchard was on the bottom of four tries from Pirates’ dominant maul, first scoring after 50 minutes before going over three more times in a 12-minute spell from the 62nd minute.
The win means they are level at the top of the table with Worcester Warriors and Ealing who also earned bonus-point victories.
“This obviously goes back a year, two years of the development around these guys, and now on a day like this to score that many, you never know, we could do it again but it would be a big ask,” Paver added of his side’s mauled tries.
“So if you get a highlight like this, Joe Walsh is going to be very happy as a coach of the line-out.”
He added: “Pritch has come off the bench, this is his third season and physically he’s really stepped up to the plate and been on the back of a superb maul like that.
“That’s what they’re there for the hookers, so a big tick in his box.”
